Spray-valve control for diesel engines.



G. C. DA-V ISON.

SPRAY VALVE CONTROL FOR DIESEL ENGINES.

APPLICATION FILED APR. 13. I916. RENEWED NOV. 16. 1918.

1,289,689. v Patented Dec. 31, 1918.

Ill

IN VE N TOR ATTORNEYS.

- London andState of UNITED STATES PATENT OFFICE.

GREGORY C; DAVISON, OF NEW LONION, CONNECTICUT, ASSIGNOR TO ELECTRIC BOAT COMPANY, OENEW YORK, N. 'Y., A CORPORATION OF NEW JERSEY.

SPRAY-VALVE CONTROL FOR DIESEL ENGINES Application filed April 13, l9165erial No. 90,961.

" To all whom it may concern:

Be it known that I, G-nneoar G. Dawson, a citizen of the United States, and a residentof New London, in the county of New Connecticut, have invented certain new and useful Imp)rovemeats "in Spra -Valve Controls for iesel Engines; and do hereby declare the following to be a full, clear, and exact description'off the in ention, such as will enable othersskilled in the art to which it apper tains to make and use the same. 0 j

This invention relates to the use of compressed air in heavy-oil internal combustion engines in connection preferably with means for storing compressed air whereby such air may he used conveniently either for spraying theoil fuel, for combination with such fuel for combustion purposes, or for startiiig the engine, and aims primarily 'to apparatus for controlling variations of air pressure and for graduated fuel il'l}80i310l'1 and combustion when the engine is started ,25 in operation.

, In the accompanying drawings, which show the preferred form of apparatus for carrying out the invention,

Figure 1 is adiagrammatic view showin a B0 heavy-oil internal pombustion en ine, an airco mpressor, a storage tank, an connected piping; and 1 ins. 2 and 3 are enlarged detail views of portions of the apparatus, Fig. 2 being a longitudinalsectionnnd 3atransverse sectionon the line ,3-'8 of ig. 2. V i he "reference numeral 1 indicates heavy-oil internal combustion engine, the main-shaft-3 of whichlis connected toan'd 0 drivewan air compressor 2.

A main pipe line 4 leads from compressor 2 to a storage tank; 5, andthe flow through this line may be controlled by the valve 7 insertedtherein. Asecond'pipe 8 5 leads directly from the compressor 2 to the scavenger valves V of the en 'ne 1 A branch pipe 9 from the pi 4 eadsto the spray valves '0 of the enggand a pipe 10" leads from the tank 5 to an ,r -startingvalve I A associated with the startingzcylinder of the enginey'T a valvelQ and the pipe 9 has inserted therein a valve -13; y

By mczinsof the parts just described, the

spray valves 4) may be supplied with air di- Speclflcation of Letters Patent the result of numerous tests merits, it has been demonstrated that upon 95 carrying. out the process in connection with of air he pi pc 10 has inserted therein Patented Dec. 31, 1918. Renewed November 16, 1918. Serial No. 262,917.

root from the compressor 2 by opening the valve 13 and closing the valve 7 for long continued running on fuel. By opening both the valves 13 and 7, the spray wives '0 may be supplied with air from the storage tank 5 for emergency running on fuel. By closing the valves 7 and 13 and opening the valve 12, the engine may be rim on compressed air from the storage tank 5 in startmg.

Certain of the parts essential to the practice of the present invention are, interposed in pipe 9 beyond valve '13 as indicated by the numeral 14 on F ig. 1.

It may be well to define the. situation sought 'tobe attained by the present process, in connection with the feeding of compressed airto the spray valves of a heavyoil "iternal combustion engine, fie-specially when such fcding is effected"merely'fhy g'is .provide a novel and important processand 0peninganor'dinary valve in the ali 'lme.

Ordinarily, when it is desired during air running m shift to fuel, there is either too great an initial sur e of air to the valves 1: or else a prolonged feed at low pressure. The herein described process consists in causing the pressureof the injecting air at 'the place of mixture with the fuel to rise rapidly from a low value to a value slightly higher than the cylinder pressure, and to so thenrise at a lower rate to a pressure ap roximately double the cylinder pressure. his situation is believed to-be the ideal one, particularly in View of actual results which aye been obtained when .it'has been observed that the pressure-variations char acteristic of the process have actually occurred at the nozzle of each spray valve. As and export an engine designed subject to a critical air pressure of 700 lbs, the torn; critical bemg here used tb indicate thelowest presfunctiomand subjectto a maximum pressure or a rcssure llIldBljWhlCll the spray valves yvll function-mosteflicieiitl andfl economically duringsubsequent running, of

sure at which the spray'valves willproperly 109 900 lbs, an apparatus similar to the very simple one hereinafter described actually mainta ns the airpressure at zero during firstanfimtesimal fraction of time aforesaid,

their causes a rapid rise of the air pressure to almost exactly 500 lbs-and thereafter, 110

the.

air is always fed 60,

4 etet'andul' n the screws 17,1; e lengths comparatively slowly raises the air pressure to the maximum or good-working! pressure of 900 lbs. The pressure of t e air, after the first rapid rise of said pressure, is lower than the critical pressure by the same number of pounds that the critical pressure is lower than-the maximum pressure.

The eculiar value of the pressure variations Just described will be further understood from the following explanation. Usually the compression pressure in a cylinder when fuel is first injected is a prom mately 450 lbs. When the initia spra pressure is a proximately 900 lbs., whic 18 as aforesai the runnin pressure under which the spray valves will function most efliciently and economically there is an expansion of the spray air clown to 450 lbs. as such air enters the cylinder, and there re sults a chilling or the niiiitiire in the vicinity of the spray nozzle, with the result that ignitiOn is retarded on account of a lowering of the temperature below the burning point of the fuel. When, however, the englne is working on full load and up to speed, the i iition is not'afiected by the feeding of air at 900 1bs. pressure, since the heated condition oi the cylinder overcomes the chilling tendency of the mixture as it expands upon injfction into the cylinder.

f an instrumentality such as disclosed in Fig. 1 at 14 be interposed in the supply line of; the spray valves of 'a heavy-oi engine, and if that instrumentality be interiorly constructed merely as shown in Figs, 2 and 3, the herein disclosed process may be carried 'very advantageously and in full satis- 1 tion of all the'probl'ems to be solved as above referred to. In Figs. 2 and- 8, the instrumentalit'yI 14 is shown as includin merel. a l of pipe 15 and a length 0 pipe 6 of a common internal diamcoaxially, in combination with a separating diaphragm 18, referably ve thin, ,whic is provided w th-a tra: 1y located aperture 1'9 of a' diameter considerably smaller than the diameter last mentioned. Pipe-length 15 is rovided with anannular flange adjacent to t c diaphragm and a collar 14 is secured onv ipe-length 15 1pm tightcmadjacent to thedia hragm.

and 16 are awn closely together and the. di lira-gm is clamped into rigidity accentua as is prefera le, at the aphragms periphery.

When such a construction is incorporated in the organization at Fi 1, compressed precise y as 'above described to the spray valve '0; merely ifragLand 'a'duated r nning of-theengine on e a case, the pressure of the air is for an indietesimal period of time zero, then rises very ing the "I e 8, never fails to cause a 1" en theval've 13 is opened, in every- 1,ese,ese

rapidly and uniformltyto a pressure value equal to approximatey 50 per cent. of the maximum pressure-ya us and then rises more slowly until it reaches the maximum. Such a control of theair pressure relativel of the spray valves gives remarkabl hig eliic ency in every respect; as to abso ute rel1ab1l1ty,as to quickly attaining high speeds, and even as to economy of fuel.

I claim:

1. The method of starting on fuel u hear 011 internal combustion en M in which th s: cylinder pressure during 11 load running on fuel is considerably less than the injecting I111 pressure, which consists in causing the pressure or the injecting air. at the place of mixture with the fuel to automatically rise from a low value to a value slightly higher than the cylinder pressure, and to then rise at a lower rate from that pressure to a considerably higher 2. The method f starting on fuel ahea oil internal combustion en I e in which t e cylinder pressure during 11 load running on fuel is approximately one-half the injectmg air pressure which consists in causing the pressure of the in ecting air at the place of mixture with the fuel to rise rapidly from a low value to a value slightly higher than the cylinder pressure, and to then rise at a lower rate to a pressure approximately double the cylinder pressure.

3. The method of starting on fuel a heav oil internal combustion en e in which t e cylinder pressure durinf ull load running on fuel is considerably essthan thefin'ectmg air pressure, which consists in guiding a flow of air under said. lniectl through and beyond; an inv'a his and abruptly constricted o ning and thereafter mix ng the air with t e fue supply to the en e. .v

l-n apparatus of the described, in. combination, a sourceoi compressed. air supply, a conduit leading therefrom, an in ternal eombustion eng ne, a spraysvalve on the en etc which said conduit is connected, an an air-bafllmg means in vthe conduit alwa s permittingthe p ofair through and eyond the same but a conduit, 7 t

5. In apparatus of the kind described, in combination, a source of compressed air supply, a conduit leading therefrom, an in ternul combustion engme, a spravwalv'e on the en no to which said conduit is connect- ,pted to e u thereat the initial flow of airthroughisaid ed, an an airebafiling means in the conduit/ rovided with a permanently-o en orifice e ess cross-sectional area, than c ercss secs tipnal area of the interior of the conduit at fi ltiusides of thehalll means. H

a crates of the l nd described, in combmat on, a source ofeompressed air sup ply, a conduit leading therefrom, an in ternal combustion engine, a spray-valve on the engine to which said conduit 1s connected, and an airbafliing plate anchored transversely of the conduit and provided with a single permanently-open orifice of less cross-sectional area than the cross-sectional .area of the interior of said conduit.

7. In apparatus of the kind described, in combination, a source of compressed air supply, a conduit leading therefrom, an internal combustion engine, a spray-valve on the engine to which said conduit is connect.- ed, and a thin air-battling plate anchored transversely of the conduit and provided with a single permanently-open orifice of considerably less cross-sectional area. than the cross-sectional area of the interior of said conduit.

8. In an apparatus of the kind described, the combination of an internal combustion engine, a spray-valve on the cylinder thereof, a source of supply of compressed air, a conduit extending from said source to the spray-valve, and a thin erforated plate arranged in the conduit f r substantially reducmg the cross-sectional area of the stream of air but always permitting the flow therethrough.

, 9. 1n apparatus of the kind described, the combination of an internal combustion engine, a source of supply of compressed air, a conduit leading from the source of supply to the interior of the cylinder, a valve device in the conduit for controlling the flow of air therethrough, and means in the eonduit for substantially reducin the crosssectional area of the stream of air but always permitting the flow therethrough.

In testimony whereof I aflix m signature.

GREGORY O. DXVISON. 

